Plastic floorings using concave portions and convex portions

ABSTRACT

The present invention relates to a new plastic flooring that is assembled by concave portions and convex portions. The plastic flooring provides space between the concave portions and convex portions. The space absorbs the heat expansion of the plastic flooring such that the deformation of the plastic flooring is prevented. Also, the space stores an adhesive on a bottom floor such that crevices between the plastic flooring are prevented.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to plastic floorings using concaveportions and convex portions, specifically to an assembly structure ofthe plastic floorings absorbing heat expansions as well as forming aspace area between the concave portions and the convex portions tominimize the deformation of the plastic floorings so that aliensubstances of a floor surface does not protrude up to the surface of thefloorings.

(b) Related Arts

Plastic floorings used for installing floors of a building areindividually manufactured so that they have a surface area of a certainstandard. The plastic floorings are used with other types of plasticfloorings to constitute the floors of the building. Typical plasticfloorings mostly have a form of a square shape having perpendicularcorners and a certain thickness. At the side surfaces of each flooring,unique assembly structures are implemented which allow them to beassemble with other types of floorings.

FIG. 8 is a cross section view of plastic floorings according to a priorart in which each plastic floorings (1) has steps in a form of stairsconnected to other plastic floorings (1′) so that multiple floorings (1,1′) are assembled in a continuous overlapping manner.

Above assembly structures, however, have the shortcomings of having aheight difference between the floorings when the floor to which thefloorings are installed is bumpy because the floorings do not closelyand firmly adjoin each other in the area connecting the floorings.

Therefore, plastic floorings (3) having concave portions (5) and convexportions (7) on the side surfaces of each flooring (3) as illustrated inFIG. 9 have been proposed to closely adjoin the connecting areas of thefloorings.

That is, the plastic flooring (3) has the convex portion (7) at the leftside of the drawing and concave portion (5) at the right side of thedrawing. The assembly of the floorings (3, 3′) is enabled by insertingthe convex portion (7) into the concave portion (5) of the other plasticfloorings (3′) and engaging the concave portion (5) with the convexportion (7) of the other plastic floorings (3′).

In floorings (3) with such a structure, however, the concave portions(5) and the convex portions (7) engage in a close manner so that whenthe heat from the bottom surface is transferred to the plastic flooring,each plastic flooring expands toward the other plastic flooring adjacentto it. As a result, distortion in the connection portion of the flooring(3) occurs as can seen in FIG. 10, which seriously degrades the qualityof the floorings.

Furthermore, many alien substances such as adhesives exist on the bottomfloor (9) to which the floorings (3) are installed. After theinstallation, the alien substances (3) protrude beyond the connectionportions, exposing itself out on the surface of the floorings. Thesealien substances weaken the adjoining force between the concave portion(5) and the convex portion (7), which causes the problem ofdeteriorating adjoining force among the floorings.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an assembly structureof plastic floorings using concave portions and convex portions whichabsorb the heat expansion of the floorings as well as preventing aliensubstances of bottom surface from protruding onto the flooring surfaceso as to minimize the distortion of the plastic floorings.

In order to achieve this object, the present invention comprises; afirst flooring having a first side surface with a concave portion and asecond side surface with a convex portion, and a second flooringassembled to the side surface of the first flooring through anengagement of the convex portions and the concave portions, said concaveportion and the convex portions\forming abutting surfaces engaging eachother in a close manner and at least one facing surface disposed so thatthey face each other and have gaps in between, providing a heatexpansion tolerance portion between the concave portion and the convexportion.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a cross section view of a plastic flooring according to thepresent invention.

FIG. 2 is a detailed view of the plastic flooring according to thepresent invention in an assembled state.

FIG. 3 is a cross section view of the plastic flooring according toanother embodiment.

FIGS. 4 to 6 are schematic drawings explaining the manner of assemblingthe plastic flooring according to the present invention.

FIG. 7 is a cross section view of the plastic flooring according toanother embodiment of the present invention.

FIG. 8 is a cross section view of the plastic flooring according to aprior art.

FIG. 9 is a cross section view of the plastic flooring according toanother prior art.

FIG. 10 is a schematic drawing explaining the distortion phenomenon ofthe plastic floorings.

DETAILED DESCRIPTION AND THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will beexplained in detail with reference to the drawings.

FIG. 1 is a cross section view of the plastic flooring according to thepresent invention. FIG. 2 is a drawing depicting the assembled plasticflooring of FIG. 1.

As illustrated in FIGS. 1 and 2, the plastic flooring comprises firstflooring (6) having a first side surface (4) with a concave portion (2)and a second side surface (10) having a convex portion (8). Secondflooring (12) is assembled with the first flooring (6) through anengagement of the concave portion (2) and the convex portion (8).

The concave portion (2) and the convex portion (8) form abuttingsurfaces (14 a, 14 b) closely engaging each other so that the firstflooring (6) and the second flooring (12) are firmly assembled. Also, apair of facing surfaces (16 a, 16 b, 18 a and 18 b), disposed with gapsin between, are formed so that a heat expansion tolerance portion S isprovided between the concave portion (2) and the convex portion (8).

First, the first flooring (6) and the second flooring (12) have flatupper surfaces. The closely abutting surfaces (14 a, 14 b) formed on theconcave portion (2) and the convex portion (8) are disposed so that theyare parallel to the upper surface of the first flooring (6) and thesecond flooring (12). More specifically, the closely abutting surface(14 a) of the concave portion (2) is defined as a surface starting frompoint A of the drawing, extending to point B. The closely abuttingsurface (14 b) of the convex portion 8 is defined as a surface startingfrom point A′ of the drawing, extending to point B′.

Here, the height of the closely abutting surface (14 b) of the convexportion (8) with respect to the lower surface of the first flooring (6)and the second flooring (12) is in fact higher than the height of theclosely abutting surface (14 a) of the concave portion (2) with respectto the lower surface of the first flooring (5) and the second flooring(12) so that the closely abutting surface (14 b) of the convex portion(8) comes into contact on the closely abutting surface (14 a) of theconcave portion (4) when the first flooring (6) and the second flooring(12) are assembled.

Consequently, the connecting portions of the first flooring (6) and thesecond flooring (12) abut closely and firmly through the closelyabutting surfaces (14 a, 14 b) provided at the concave portion (2) andthe convex portion (8). Thus, even when the floor surface (not shown) isbumpy, the height difference between the first flooring (6) and thesecond flooring (12) due to the bumps are suppressed.

Also, the facing surfaces formed at the concave portion (2) and theconvex portion (8) consist of the slanted surfaces (16 a, 16 b)maintaining a certain angle with the upper surface of the first flooring(6) and the second flooring (12) and perpendicular surfaces (18 a, 18 b)connecting the slanted surfaces (16 a, 16 b) with each closely abuttingsurface (14 a, 14 b). The slanted surface (16 a) and the perpendicularsurface (18 a) formed at the concave portion (2) maintain a certain gapwith the slanted surface (16 b) and the perpendicular surface (18 b)formed on the convex portion (8), thereby providing space between theconcave portion (2) and the convex portion (8).

More specifically, the slanted surface (16 a) of the concave portion (2)is defined as a surface starting from point C of the drawing, extendingto point D of the drawing. The slanted surface (16 b) of the convexportion (8) is defined as a surface starting from point C′ of thedrawing, extending to point D′ of the drawing. Also, the perpendicularsurface (18 a) of the concave portion (2) is defined as a surfacestarting from point D of the drawing, extending to point A of thedrawing. The perpendicular surface (18 b) of the convex portion (8) isdefined as a surface starting from point D′ of the drawing, extending topoint A′ of the drawing.

Particularly, the perpendicular surfaces (18 a, 18 b) of the concaveportion (2) and the convex portion (8) face each other with a gap of d1in between. The slanted surfaces (16 a, 16 b) of the concave portion (2)and the convex portion (8) maintain angles of α and β with respect to avirtual normal perpendicular to the upper surface of the first flooring(6) and the second flooring (12). α and β are configured so that thefollowing conditions are met.

[Mathematical Formula]α=65˜75°, β=65˜75°, α≧β

Above conditions are necessary to facilitate the engagement between theconcave portion (2) and the convex portion (8). If α is smaller than β,the insertion of the convex portion (8) into the concave portion (2) isnot smooth, which causes such problems as fracture in the convex portion(8) during the assembly of the first flooring (6) and the secondflooring (12).

In this manner, the structure of the concave portion (2) and the convexportion (8) forms a space, that is, a heat expansion tolerance portion(S), between the concave portion (2) and the convex portion (8). Theheat expansion tolerance portion (S) absorbs the heat expansion of thefirst flooring (6) and the second flooring (12) when the first flooring(6) and the second flooring (12) heat expands from the heat of thebottom surface, allowing the assembled floorings to maintain a flatshape, consequently, preventing the deformation of the floorings.

Furthermore, the heat expansion tolerance portion (S) traps the aliensubstances such as adhesives on the floor surface within its interior,effectively preventing the phenomena of the alien substances protrudingon to the surface of the first flooring (6) and the second flooring (12)as well as formation of crevice of the first and second floorings (6,12) by the alien substances.

On the other hand, the first flooring 6 and the second flooring (12)forms an additional heat expansion tolerance portion (S′) between thefirst side surface (4) with the concave portion (2) and the second sidesurface (10) with convex portion (8) as well as the heat expansiontolerance portion (S) formed by the concave portion (2) and the convexportion (8) of the first and the second floorings (6, 12). Theadditional heat expansion tolerance portion (S′) supplements thefunction of absorbing the heat expansion of the flooring and preventionof the crevices.

For such purposes, the first side surface (4) provides a supplementalslanted surface (20 a) starting from the upper surface of the firstflooring (6) extending toward the interior of the first flooring (6) andconnected to the slanted surface (16 a) of the concave portion (2). Thesecond side surface (10) provides a supplemental slanted surface (20 b)starting from the upper surface of the second flooring (12) extendingtoward the interior of the second flooring (12) and connected to theslanted surface (16 b) of the convex portion (8). Thus, additionalspace, that is the heat expansion tolerance portion (S′), is formedbetween the supplemental slanted surfaces (20 a, 20 b).

More specifically, the supplemental slanted surface (20 a) of the firstside surface (4) is configured as a surface having an angle of χ withrespect to a virtual normal, starting from point E and extending topoint C of the drawing. The supplemental slanted surface (20 b) of thesecond side surface (10) is configured as a surface having an angle of δwith respect to a virtual normal, starting from point E and extending toC′ of the drawing.

Preferable, χ and δ satisfy the following conditions.

[Mathematical Formula 2]χ=0˜8°, δ=0˜8°, χ≧δ, χ+δ=0˜16°

These conditions are for absorbing the heat expansion of the flooringsby forming sufficient heat expansion tolerance portion (S′) between thefirst side surface (4) and the second side surface (10) while enablingthe holding of the aliens substances therein. If χ+δ is set below 0°,then the heat expansion tolerance portion cannot perform its functionwhereas if the χ+δ is set above 16°, then the strength of the first andthe second floorings (6, 12) decreases because of the excessive heatexpansion tolerance portion so that problems such as fracturing at thecorners occur when the floorings are subject to pressure.

Furthermore, the first side surface (4) provides a perpendicular surface(22 a) connected to the closely abutting surface (14 a) of the concaveportion (2) at the lower surface of the first flooring (6). The secondside surface (10) provides a perpendicular surface (22 b) connected tothe closely abutting surface (14 b) of the convex portion (8) at thelower surface of the second flooring (12). The perpendicular surfaces(22 a, 22 b) of the first and the second side surfaces (4, 10) maintaina gap of d2 between each other, forming a heat expansion toleranceportion (S″).

The heat expansion tolerance portion (S″) defined by the gap d2 contactsthe floor surface directly. Therefore, it absorbs the heat expansionwhich occurs when the lower surfaces of the first and the secondfloorings (6, 12) expand because of the heat from the bottom floor aswell as directly holding alien substances existing on the bottom floorso that the alien substances do not protrude beyond the closely abuttingsurface (14 a) and (14 b) of the concave portion (2) and the convexportion (8).

Therefore, it is preferable to configure the heat expansion toleranceportion (S″) as identical to above d1 or satisfy the followingconditions considering the heat applied to the floorings and thecondition of the flooring surfaces to which the floorings are beinginstalled.

[Mathematical Formula 3]d 2=2×d 1

In these plastic floorings according to the present embodiment, theconnecting portions of the first and the second floorings (6, 12) arefirmly and closely abutted by the engagement of the closely abuttingsurfaces (14 a, 14 b) of the concave portion (2) and the convex portion(8) while the heat expansion tolerance portions (S, S′ and S″) absorbthe heat expansion of the floorings and holds the alien substances ofthe floor surface, providing the merit of preventing the deformation ofthe floorings caused by the heat expansion and the alien substances.

Here, when the thickness of the floorings is assumed to be 1, preferableconfigurations are as follows: the thickness from the upper surface ofthe first and the second floorings (6, 12) to the slanted surface (14 a,14 b) of the concave portion (2) and the convex portion (8) is ¼, thethickness of the slanted surface (16 a, 16 b) of the concave portion (2)and the convex portion (8) is ¼, the thickness of the perpendicularsurface (18 a, 18 b) of the concave portion (2) and the convex portion(8) is ¼, and the thickness from the closely abutting surface (14 a, 14b) of the concave portion (2) and the convex portion (8) to the lowersurface of the first and the second floorings (6) and (12) is ¼.

On the other hand, the plastic floorings according to the presentinvention can be assembled in the following manner using the engagementstructure of the concave portion (2) and the convex portion (8).

First, as shown in FIG. 4, the concave portions (2) are formed at thetwo adjacent side surfaces and the convex portions (8) are formed on theremaining two other side surfaces of each plastic flooring. The convexportion (8) of the second flooring (24) is assembled by fitting it intothe concave portion (2) of the first flooring (22). The convex portion(8) of the third flooring (26) is assembled by fitting it into theconcave portion (2) of the first and the second floorings (22, 24).

As another embodiment, a first group of plastic flooring (28 a, 28 b)has the structure having the concave portions at three adjacent sidesurfaces and having convex portion (8) at remaining one side surface asshown in FIG. 5. A second group of plastic floorings (30) has thestructure of having the convex portions (8) at three adjacent sidesurfaces and the concave portion (2) at one remaining side surface.

To the concave portions (2) of the first flooring (28 a) belonging tothe first group, the convex portions (8) of the second floorings (28 b)are assembled in one direction. To the side surface of the plasticfloorings (28 a, 28 b) belonging to the first group, the plasticfloorings (30) of the second group are connected and assembled.

In still another embodiment as shown in FIG. 6, the plastic flooring(32) of the first group has the concave portions (2) formed at all fourside surfaces whereas the plastic flooring (34) of the second group hasthe convex portions (8) formed on all four side surfaces. At all fourside surfaces of the plastic flooring (32) belonging to the first group,the plastic floorings (34) of the second group are connected andassembled.

The plastic flooring assembled in these manners can be formed wholly ofplastic while it can also comprise a substrate layer (36) and a surfacelayer (38) located above the upper surface of the substrate layer (36)attributing pattern to the floorings, and a balance layer (40) whichprevents the contraction and expansion of the flooring and maintainingthe flatness as shown in FIG. 7.

For example, the surface layer (38) can be of natural material of apatterned wood layer and the balance layer (40) is a glass fiberimpregnated with plastic. The plastic floorings can establish thedimension stability by the balance layer (40).

Preferably, the corners of the surface layer (38) and the balance layer(40) are beveled so that the beveled portion along with the heatexpansion tolerance portion (S) absorb the heat expansion of the plasticflooring caused by the heat from the bottom surface; thus, preventingthe occurrence of the height difference between the floorings.

According to the present invention, the formation of the heat expansiontolerance portion (S) between the concave portion (2) and the convexportion (8) has the effect of minimizing the deformation of the plasticfloorings by absorbing the heat expansion of the floorings andpreventing the alien substances of the bottom floor from protruding upto the surface of the floorings.

1. A plastic flooring comprising: a first flooring having an uppersurface, a lower surface, and a first side surface with a concaveportion; and a second flooring having a flat upper surface, a lowersurface, and a second side surface with a convex portion, said secondflooring assembled to the side surface of the first flooring byinserting the convex portion into the concave portion, said concaveportion and the convex portion each comprise, slanted surfaces formed ona top surface of the concave portion and the convex portion toward theupper surface of the first and the second floorings and maintaining acertain angle with respect to the upper surface of the first and thesecond floorings, abutting surfaces formed on a bottom surface of theconcave portion and the convex portion toward the lower surface of thefirst and the second floorings and engaging each other in a closemanner; and perpendicular surfaces connecting the slanted surfaces andthe abutting surfaces, wherein the abutting surfaces of the concaveportion and the convex portion being parallel to the upper surfaces ofthe first and the second floorings, and both of the slanted surface andthe perpendicular surface of the concave portion being disposed facingwith gaps between both of the slanted surface and the perpendicularsurface of the convex portion so that a heat expansion tolerance portionis provided between the concave portion and the convex portion.
 2. Theplastic flooring of claim 1, wherein the slanted surface of the concaveportion maintains an angle of α with respect to a normal perpendicularto the upper surface of the first flooring, and the slanted surface ofthe convex portion maintains an angle of β with respect to the normal,wherein the α and β satisfy the following conditions:α=65˜75°, β=65˜75°, α≧β.
 3. The plastic flooring of claim 1, wherein thefirst side surface provides a supplemental slanted surface starting fromthe upper surface of the first flooring toward interior of the firstflooring and connected to the slanted surface of the concave portion,and the second side surface provides a supplemental slanted surfacestarting from the upper surface of the second flooring toward theinterior of the second flooring and connected to the slanted surface ofthe convex portion so that a heat expansion tolerance portion isprovided between the supplemental slanted surfaces of the first and thesecond side surfaces.
 4. The plastic flooring of claim 3 wherein, thesupplemental slanted surface of the first side surfaces maintains anangle of χ with respect to a normal perpendicular to the upper surfaceof the first flooring, and the supplemental slanted surface of thesecond side surfaces maintains an angle of δ with respect to the normal,wherein χ and δ satisfy the following conditions:χ=0˜8°, δ=0˜8°, χ≧δ, χ+δ=0˜16°.
 5. The plastic flooring of claim 1,wherein the first side surface provides a perpendicular surfaceconnected to the abutting surface of the concave portion at the lowersurface of the first flooring, and the second side surface provides aperpendicular surface connected to the abutting surface of the convexportion at the lower surface of the second flooring so that a heatexpansion tolerance portion is provided between the perpendicularsurfaces of the first and second side surfaces.
 6. The plastic flooringof claim 5 wherein the gap d1 between the perpendicular surfaces formedon the first and the second side surfaces are identical to the gap d2between the perpendicular surfaces formed between the concave portionand the convex portion.
 7. The plastic flooring of claim 5, wherein thegap d1 between the perpendicular surfaces formed on the first and thesecond side surfaces is twice the gap d2 between the perpendicularsurfaces formed on the concave portion and the convex portion.
 8. Theplastic flooring of claim 1, wherein the thickness starting from theupper surface of the first and the second floorings to the slantedsurfaces of the concave portion and the convex portion, the thickness ofthe slanted surfaces of the concave portion and the convex portion, thethickness of the perpendicular surfaces of the convex portion and theconcave portion, and the thickness starting from the abutting surfacesof the concave portion and the convex portion to the lower surface ofthe first and the second floorings are ¼ of the total thickness of thefirst and the second floorings.
 9. The plastic flooring of claim 1,wherein the concave portions are formed on two adjacent sides of theplastic flooring and the convex portions are formed on the two remainingside surfaces.
 10. The plastic flooring of claim 1, wherein the plasticfloorings comprise a first group of floorings in which the concaveportions are formed on three adjacent side surfaces and the convexportions are formed on one remaining side surface, and a second group offloorings in which the convex portions are formed on three adjacent sidesurfaces and the concave portions are formed on the remaining one sidesurface.
 11. The plastic flooring of claim 1, wherein the plasticfloorings include a first group of floorings in which the concaveportions are formed on all four sides of the plastic flooring and asecond group of floorings in which the convex portions are formed on allfour side surfaces of the plastic flooring.
 12. The plastic flooring ofclaim 1, wherein the first and the second floorings comprise, asubstrate layer composed of plastic; a surface layer located at theupper surface of the substrate layer attributing pattern; and a balancelayer located at the lower surface of the substrate layer attributingdimension stability.
 13. The plastic flooring of claim 12 wherein thesurface layer and the balance layer are beveled.